The invention relates to an arrangement for filling a mold from below with a casting mass from a casting container through an uptake into the molding sand of the mold and for facilitating the flowing in of the casting mass rising up from below and entering into the mold.
The casting mass is subjected to a feed pressure, which, after casting, must be maintained sufficiently long until the casting mass has rigidified in the mold so that it cannot return into the casting container. Only then is it possible to remove the feed pressure and to exchange the filled mold for a new mold for the next casting. The time required for cooling off of the casting mass filled into the mold slows down the casting process because the filling of a mold via a riser passageway for the casting mass is a very economical method, which can also be used for molds made of molding sand, which molds can be manufactured quickly and in large numbers; the waiting periods required for the cooling off of the casting mass are therefore especially annoying.
The basic purpose of the invention is therefore to provide an arrangement including an associated mold in such a manner that the feed pressure for feeding of the casting mass from the casting container into the mold can cease immediately after the mold has been filled with casting mass.
The purpose is attained according to the invention wherein directly after the filling of the mold has been completed, the molding sand in which is provided the uptake is interrupted and is thus closed off so that the mold can be separated from the casting container. The mold and the mold container are flow-coupled in relationship to the casting mass and the feed pressure can thereafter be removed. A new mold can directly thereafter be flow-connected to the casting container so that the casting process can already be started anew when the earlier cast mold has not yet rigidified. Such a casting method can therefore be advantageously utilized in a continuously running manufacturing process.
A particularly advantageous development of the invention is experienced by the casting method when the casting mass stored in the casting container is subjected to a pneumatic feed pressure on its surface, and the casting mass is pressed through at least one vertically extending first uptake terminating at one end in the casting mass, and through a second uptake aligned with the first uptake and forming with same a common uptake pipeline for facilitating the filling of the casting mass into the mold provided above the uptake. The entire uptake pipeline extends hereby vertically and is accessible in the area of the second uptake to a constriction carried out in the mold.
Thus it is possible that a thin blocking slide, for example a metal strip, is moved into the uptake transversely with respect to its axis and covering its cross section. The metal strip can thereby be guided by a piston rod or also manually into the area of the uptake through the molding sand. It is even easier when the uptake is constricted in a preferably short partial area on a lower part of the mold through a horizontal force of at least one preferably hydraulically operated piston rod, which force is applied transversely with respect to its axis, and moves and/or compresses the molding sand; the uptake is thereby closed off merely by moving and/or compressing the molding sand, whereby immediately after the flow into the uptake is interrupted the feed pressure onto the surface of the casting mass is stopped so that the desired continuous operating process is achieved because the mold can now be immediately replaced.
Such a mold, which is suited for the method of the invention, is characterized, for example, in such a manner that a channel is provided in the molding sand, which channel extends preferably into the vicinity of the uptake, is oriented transversely with respect to the axis of the uptake, is formed into the molding sand and is displaced by the piston rod. The channel can be provided with a plug, which plug can be forced into the uptake by the piston rod in such a manner that same is blocked. Instead it is also possible that the channel is designed as a slide guide, in which a disk-shaped slide is provided so that a flow passage provided in the slide and adapted to the flow cross section of the uptake pipeline is just aligned with the uptake, whereby the slide with the help of the piston rod can be moved so far that the uptake pipeline is blocked. In the case of a stationarily arranged mold, the uptake lies either in or parallel to the mold parting plane of the mold, whereas the uptake in a mold, which is lying on its side 90xc2x0 offset from the aforementioned position, is arranged perpendicularly with respect to the mold parting plane. The channel must be constructed wider in a mold which is lying on its side so that a guiding in and a relative movement of the piston rod for closing of the uptake is possible.